Bests & Worsts Reviews from Amazon

Bought this to check drywall at the in-law's house. There was a roof leak near their chimney that caused damage to the interior drywall. Called someone in to diagnose/repair the leak but before paying someone to fix the drywall we wanted to see if the leak was actually fixed. Bought this a few days before it rained for the first time since the repair and sure enough it found moisture in the damaged area again. Had them come back to check their work. Guy said it was residual moisture from the first time it leaked (from 2 months ago... sure, ok) but quickly backtracked after I showed him the photos of the 5% reading before it rained and +20% an hour after the rain started up again.